March 2003

By Steve Stefanik

As we approach the Vernal Equinox, which occurs on March 20 at 8:00 p.m. EST, the daylight hours are getting longer and the night is getting shorter. As a result when darkness encroaches two planets are already high in the sky.

The planet Saturn is directly overhead between "the horns" of the constellation Taurus. Look for the yellow-orange orb east of the first magnitude red-orange star Aldebaran, which is "the eye" of the bull and south of the bright first magnitude star Capella, which is the brightest star in the nearby constellation Auriga the charioteer. Saturn is the brightest of the three at magnitude zero. Now would be a good time to catch a glimpse of its ring system, which is as "open" as they get in the next 30 years. All you need is some binoculars or even a small telescope to view them. You may even spot the dark gap between the A and B rings, which is known as the Cassini division named for its discoverer.

Jupiter, the largest of all the planets, is well placed high in the eastern sky between the constellations Gemini the twins and Leo the lion. Look for the brilliant –2.4 magnitude planet near M44 "the beehive" open star cluster in the nearby constellation Cancer the crab. You may be able to make out the two dark bands of the north and south equatorial belts with just binoculars. You’ll be able to discern cloud formations, storms, swirls, festoons, and eddies through a moderate sized telescope with an aperture of 6 inches or more. In addition, this year we are aligned in the same plane as Jupiter so that we experience occultations, eclipses, and transits of its four largest moons, Io, Europa, Ganymede, and Callisto as they orbit the giant planet.

While you are outside enjoying the view you can’t help but notice that the familiar winter constellations of Taurus, Canis Major and Orion are past the zenith and on their way toward setting in the west as the constellations of Cancer, Leo and Virgo are rising in the east, a sure sign of spring.

Two other naked-eye planets are also visible but don’t rise until the early hours of the morning. The planet Mars rises several hours after midnight but is best seen just before dawn in the southeast among the stars of the constellation Sagittarius. Look for the rusty red 0 magnitude meanderer near its nemesis Antares the bright red first magnitude star in the constellation Scorpius. Although it is still quite small in angular size because it is still very far away, this summer it will be as big and as bright as it will get in the next 60,000 years when it reaches opposition.

The planet Venus makes a brief appearance each morning low on the eastern horizon as the sun rises but is quickly lost in its glare. You might mistake this –4.0 magnitude beacon as an approaching airplane coming in for a landing.

Two other planets are in the morning sky along with Mars and Venus but you’ll need a telescope to spot them. Neptune is in close conjunction with Venus, separated by only 11 arc minutes on the morning of the 12^th . Uranus is in an even closer conjunction with Venus, only 10 arc minutes on the morning of the 28^th.

The planet Mercury is at superior conjunction behind the sun this month.